NEW YEAR is a time for beginnings; it is also an apt moment for closure. The eminent conductor Kurt Sanderling has decided to lay down his baton. After 70 years on the podium, he is entitled to early retirement and a bask among the gold discs on his wall. Musicians are rueing his departure, while admiring its dignified restraint.

Sanderling, who turns 90 in September, is the last conductor to have experienced the symphonies of Dmitri Shostakovich in the raw. Having fled Hitler's Germany for Stalin's paradise, he befriended the composer in wartime Siberia, where the Eighth Symphony was premiered. Sanderling was selective about the symphonies he liked, never bothering much, for instance, with the widely-performed Seventh. But no man has given more performances of the wintry, thinly-scored 15th Symphony, and always from a manuscript with the composer's handwritten markings.

Contrary to the current academic fad for regarding Shostakovich as a cowed Soviet citizen, Sanderling avows that the "dominant theme of his life" was anti-Stalinism. He endorsed the authenticity of Solomon Volkov's disputed memoir of the composer and his interpretations are enriched by the ambivalences of survival in a terror state.

Sanderling was too fastidious a man to capitalise on his intimacy with genius in a blether of press interviews. His memories of Shostakovich were heard only in rehearsal, to illustrate a musical allusion. They will never be consigned to paper, more's the pity.

Returning to Berlin in 1960, he formed behind the Wall an ensemble to rival Karajan's Philharmonic. His Western career began in London in 1970 and flourished with the Philharmonia, whose recent seasons he opened with the pianist Mitsuko Uchida. Many orchestras will lament his exit. Simon Rattle phoned up, imploring him to preside over a Berlin Philharmonic tribute in September, offering to conduct half the concert himself.

Sanderling, however, stood firm. He wants to be remembered at his best, he said, not as a frail old man or museum piece. His stance is commendable. Most conductors carry on beating until they drop, usually to the detriment of music and their own posterity. Many who remember Karajan or Karl Bohm only in their dotage, dozing off in mid-symphony, struggle to picture them in their pomp. The fault is theirs, not ours: they should have checked out, like Sanderling, still erect and alert. All else is pathos.

Conductors are by no means the worst hangers-on. Arthur Rubinstein played truckloads of wrong notes in his eighties and Isaac Stern made many squirm in his years of decline.

There are, of course, exceptions who bloom in the evening of life. The Buena Vista Social Club of Havana and the Russian maestro-maker Ilya Musin had been frozen alive by political oppression. The near-octogenarian Ivry Gitlis, who plays in a Taneyev festival next week at the Wigmore Hall, suffered from music-biz prejudices.

There are also living testimonies whose very survival on stage is morally valuable. I would not have missed seeing Pablo Casals, at 90-plus, seated and half-slumped, directing one of his own cantatas with little more than a beady eye and a beam of grace. Whatever his frailty, the force of personality was felt by everyone in the auditorium - his triumph over Franco's tyranny.

For every Casals, however, there are 10 Stokowskis stumbling through a haze of lost memory; for every Callas, who quit early but past perfection, there are a dozen Caballes and Kiris setting out on "one last tour" without a twitch of self-criticism.

I have sympathy for musical stragglers. Many fear to quit because they have nothing to fall back on - few friends beyond the green-room door, no intellectual interests, no interior life. Kurt Sanderling lacks these constraints. A reflective man with a well-stocked private library and warm family, he can enjoy his nineties in the glow of a reading lamp, knowing that his work is done, his status secure.